1. Field of the Invention
This invention relates to an optical disk apparatus for outputting a reproduction video signal based on a still image file read from an optical disk, and particularly to a DVD apparatus having a reproduction function of moving image data and a still image file.
2. Description of the Related Art
Conventionally, a DVD player for reading moving image data recorded on a DVD and outputting a video signal (moving image) based on this moving image data has become popular. A reproduction video signal outputted from the DVD player is inputted to a display device having a display screen, for example, a television image receiver and is displayed on this display device. Sound data and moving image data compressed by MPEG2 are recorded on the DVD. The DVD player is provided with a decoder of MPEG2.
Also, there are many users who record a photography image (still image) taken by a digital camera on a CD and retain the image, and the users desired to reproduce the photography image recorded on the CD by the display device connected to the DVD player. In consideration of this desire, means for providing a function of reproducing a still image file in the DVD player has been proposed. By the way, various file formats of the still image file include JPEG, GIF, PICT, etc., and decoders for the file formats differ from one another. Therefore, it is impractical in view of costs to make a body of a DVD player cope with still image files of all the file formats.
Thus, since a pickup image picked up is a file of a JPEG format in a general digital camera, in order to suppress an increase in cost of the body and meet a desire of the users, the conventional DVD player is constructed so that a function (decoder) of reproducing a still image file of the JPEG format is provided and the still image file of the JPEG format can be reproduced (still images of the other file formats cannot be reproduced).
The DVD player having a function of reproducing the still image file of this JPEG format is generally called a DVD player with a JPEG reproduction function. When reproduction of a still image file is instructed, it is determined whether or not a file format of its still image file is a JPEG format (it is determined whether or not an extension of a file is JPG), and when the file format is the JPEG format, reproduction processing of the still image file specified is started. When the file format is not the JPEG format, error processing is performed and the users are notified that the still image file cannot be reproduced.
Incidentally, in order to be constructed so as to be able to cope with plural code patterns without preparing plural decoding parts in an information reproducing apparatus, means for recording a program (decoding processing program) used in decoding processing on a record medium and decoding data read from the record medium by the decoding processing program read from the record medium at the time of reproduction is proposed in JP-A-2002-140196. However, since this proposal presumes that the program (decoding processing program) used in decoding processing is recorded on the record medium, when a user writes a still image file on a CD, a corresponding decoding processing program must be written together with this still image file and an operation for writing the still image file on the CD becomes complicated and also time necessary for processing becomes long and as a result, operability is deteriorated.
The JPEG format includes formats of base line JPEG, progressive JPEG and lossless JPEG. The progressive JPEG is JPEG for gradually displaying an image. The DVD player with a JPEG reproduction function includes a decoder which does not cope with the progressive JPEG for the purpose of suppressing an increase in cost of the body as described above and a photography image of a digital camera recorded on a CD is reproduced and can be viewed by a display device connected to the DVD player.
As a result of this, when reproduction of a still image file of the progressive JPEG format is instructed, a file extension is JPG, so that the DVD player starts reproduction processing and at a point in time of detecting that decoding cannot be performed in the decoder, error processing is performed. Because of this, there was a problem that time necessary to notify the user that the still image file whose reproduction is instructed cannot be reproduced is long and operability of the user is deteriorated.